Sleep staging is important for understanding the quality of sleep and for the diagnosis of various sleep disorders (e.g. insomnia, parasomnias, REM behavior disorder, etc.). There are 5 stages of sleep (according to the new AASM guidelines) which include Stage W (wake), Stage N1 (lightest non-REM sleep), Stage N2 (mid-level stage of non-REM sleep), Stage N3 (deep non-REM sleep), and Stage REM (rapid eye movement sleep where dreaming occurs).
Conventionally, sleep staging of a person is done via a full clinical polysomnography (PSG) study where a technician splits the night into 30 second epochs or time periods and then assigns one of the 5 stages of sleep to each epoch. At a minimum, a PSG study requires signals that are relatively obtrusive and uncomfortable, including electroencephalography (EEG), electromyography (EMG), and electrooculography (EOG). The abundance of sensors required to detect the EEG, EMG, and EOG signals interferes with the person's sleep and prevents a representative sample of sleep from being obtained. Additionally, the PSG study is typically done outside of the home and in a sleep lab, making the environment different than the person is used to. Also, staging of the PSG study requires a trained technician to manually review the PSG study which can often take several hours and is highly subjective.
Therefore, there is a strong need for a cost-effective, and efficient solution that overcomes the aforementioned issues. The present invention addresses such a need.